/**
* hoverIntent is similar to jQuery's built-in "hover" function except that
* instead of firing the onMouseOver event immediately, hoverIntent checks
* to see if the user's mouse has slowed down (beneath the sensitivity
* threshold) before firing the onMouseOver event.
* 
* hoverIntent r5 // 2007.03.27 // jQuery 1.1.2+
* <http://cherne.net/brian/resources/jquery.hoverIntent.html>
* 
* hoverIntent is currently available for use in all personal or commercial 
* projects under both MIT and GPL licenses. This means that you can choose 
* the license that best suits your project, and use it accordingly.
* 
* // basic usage (just like .hover) receives onMouseOver and onMouseOut functions
* $("ul li").hoverIntent( showNav , hideNav );
* 
* // advanced usage receives configuration object only
* $("ul li").hoverIntent({
*	sensitivity: 7, // number = sensitivity threshold (must be 1 or higher)
*	interval: 100,   // number = milliseconds of polling interval
*	over: showNav,  // function = onMouseOver callback (required)
*	timeout: 0,   // number = milliseconds delay before onMouseOut function call
*	out: hideNav    // function = onMouseOut callback (required)
* });
* 
* @param  f  onMouseOver function || An object with configuration options
* @param  g  onMouseOut function  || Nothing (use configuration options object)
* @author    Brian Cherne <brian@cherne.net>
*/
(function($) {
	$.fn.hoverIntent = function(f,g) {
    // default configuration options
    var cfg = {
    	sensitivity: 7,
    	interval: 100,
    	timeout: 0
    };
    // override configuration options with user supplied object
    cfg = $.extend(cfg, g ? { over: f, out: g } : f );

    // instantiate variables
    // cX, cY = current X and Y position of mouse, updated by mousemove event
    // pX, pY = previous X and Y position of mouse, set by mouseover and polling interval
    var cX, cY, pX, pY;

    // A private function for getting mouse position
    var track = function(ev) {
    	cX = ev.pageX;
    	cY = ev.pageY;
    };

    // A private function for comparing current and previous mouse position
    var compare = function(ev,ob) {
    	ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
    	// compare mouse positions to see if they've crossed the threshold
    	if ( ( Math.abs(pX-cX) + Math.abs(pY-cY) ) < cfg.sensitivity ) {
        $(ob).unbind("mousemove",track);
        // set hoverIntent state to true (so mouseOut can be called)
        ob.hoverIntent_s = 1;
        return cfg.over.apply(ob,[ev]);
    	} else {
        // set previous coordinates for next time
        pX = cX; pY = cY;
        // use self-calling timeout, guarantees intervals are spaced out properly (avoids JavaScript timer bugs)
        ob.hoverIntent_t = setTimeout( function(){compare(ev, ob);} , cfg.interval );
    	}
    };

    // A private function for delaying the mouseOut function
    var delay = function(ev,ob) {
    	ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
    	ob.hoverIntent_s = 0;
    	return cfg.out.apply(ob,[ev]);
    };

    // A private function for handling mouse 'hovering'
    var handleHover = function(e) {
    	// next three lines copied from jQuery.hover, ignore children onMouseOver/onMouseOut
    	var p = (e.type == "mouseover" ? e.fromElement : e.toElement) || e.relatedTarget;
    	while ( p && p != this ) { try { p = p.parentNode; } catch(e) { p = this; } }
    	if ( p == this ) { return false; }

    	// copy objects to be passed into t (required for event object to be passed in IE)
    	var ev = jQuery.extend({},e);
    	var ob = this;

    	// cancel hoverIntent timer if it exists
    	if (ob.hoverIntent_t) { ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t); }

    	// else e.type == "onmouseover"
    	if (e.type == "mouseover") {
        // set "previous" X and Y position based on initial entry point
        pX = ev.pageX; pY = ev.pageY;
        // update "current" X and Y position based on mousemove
        $(ob).bind("mousemove",track);
        // start polling interval (self-calling timeout) to compare mouse coordinates over time
        if (ob.hoverIntent_s != 1) { ob.hoverIntent_t = setTimeout( function(){compare(ev,ob);} , cfg.interval );}

    	// else e.type == "onmouseout"
    	} else {
        // unbind expensive mousemove event
        $(ob).unbind("mousemove",track);
        // if hoverIntent state is true, then call the mouseOut function after the specified delay
        if (ob.hoverIntent_s == 1) { ob.hoverIntent_t = setTimeout( function(){delay(ev,ob);} , cfg.timeout );}
    	}
    };

    // bind the function to the two event listeners
    return this.mouseover(handleHover).mouseout(handleHover);
	};
})(jQuery);